# Algorithm to Get a Product score based on rating

I am trying to device a algo for product score. Here are the inputs

1. User rates a product on 5 different criteria out of 10
2. Each criteria has a different weightage with all adding up to 100%
3. There are 3 types of user expert, inter, beginner
4. Again weightage of users is different

Here is what i have thought

1. We get the final score for each user out of 10 by

User score = CriteriaScore 1 * Weight 1 + CriteriaScore 2 * Weight 2 + ... + CriteriaScore 5 * Weight 5

2. Expert gets a weight of 3, inter get a weight of 2 and beginner gets a weight of 1

Final score = Avg Final score of expert * WeightExpert + Avg Final score of inter * WeightInter + Avg Final score of beginner * WeightBeginner

But my formula doesn't take into account How many people rated the product. How do i get this data into the picure.

Any other suggestion is also welcome

-

$$\frac{ w_1 S_1 + w_2S_2 + w_3S_3}{w_1C_1 + w_2C_2 + w_3C_3}$$
Where $S_i$ is the sum of the scores from the people with "level" $i$, and $C_i$ is the number of users of "level" $i$. Thus, if level "1", "2", and "3" are, respectively, "expert," "inter," and "beginner," the formula would be:
$$\frac{3S_1 + 2S_2 + S_3}{3C_1+2C_2 + C_3}$$